Various types of equipment are known to provide patients with oxygen or oxygen-enriched air supplies in order to sustain life-support systems or relieve symptoms of various types of debilitating diseases, particularly of the lungs. In the past, pure oxygen or oxygen-enriched gases supplied from pressurized cylinders have been used. However, such cylinders are cumbersome and have a relatively short life before they need to be refilled or replaced. Oxygen concentrators using the principle of pressure swing adsorption were designed to overcome these obstacles.
Generally, the pressure swing adsorption technique, hereinafter referred to as PSA, is used to concentrate a selected gas out of a mixture of gases. Particularly, the oxygen concentrator is a device used to concentrate oxygen out of ambient air and to supply the oxygen concentrated mixture for medical or other purposes, where an oxygen rich gas is required. The general type and operating principles of PSA apparatus with which this invention is concerned are described in U.S. Pat. Nos. 3,564,816; 3,636,679; 3,717,974; 4,802,899; 5,531,807 and 5,871,564, among others. For example, a pressure swing adsorption apparatus may include one or more adsorbers, each having a fixed sieve bed of adsorbent material to fractionate at least one constituent gas from a gaseous mixture by adsorption into the bed, when the gaseous mixture from a feed stream is sequentially directed through the adsorbers in a co-current direction. While one adsorber performs adsorption, another adsorber is simultaneously purged of its adsorbed constituent gas by part of the product gas that is withdrawn from the first or producing adsorber and directed through the other adsorber in a counter-current direction. Once the other adsorber is purged, the feed stream at a preset time is then directed to the other adsorber in the co-current direction, so that the other adsorber performs adsorption. The first adsorber then is purged either simultaneously, or in another timed sequence if there are more than two adsorbers, all of which will be understood from a reading of the above described patents. While oxygen concentrators have proven to be very useful for many medical and other applications, those known to us will generate a noise level that can limit their usefulness in many environments, such as public locations or at health treatment facilities.
Additionally, the compact size of this device requires internal components to be tightly packed and in close proximity of each other. While the compact size of the device gives the apparatus a distinct advantage, difficulty may be experienced in repair or maintenance. Removal or repair of a particular component often requires the removal of surrounding components so that access may be obtained.
Therefore, what is needed in the art is a compact and mobile oxygen concentrator with reduced noise.
Furthermore, what is needed in the art is an oxygen concentrator with easily accessible components to assist in maintenance and repair.